Durock is installed using a thin bed of thinset beneath the boards, followed by backerboard screws through the Durock and into the floor or wall that you are installing it to. According to Floorelf.com, with the Durock cement boards in place, the floor or wall has a strong, secure surface on which tiles can be placed securely. You need a trowel, power saw, electric screwdriver and alkali-resistant mesh tape to complete the installation.Continue Reading
Lay the boards onto the floor or against the wall, covering the entire area. Leave a gap of 1/16 inch to 1/8 inch between the boards to allow for movement in the floor or wall beneath. Stagger the board placement so that no four corners meet. Cut the boards to fit using the power saw or by scoring the board with a utility knife and snapping it. Doorways may need to be undercut in order to fit the boards beneath them.
Remove the fitted boards one row at a time and trowel a layer of thinset over the floor or wall. Place the boards back over the thinset before moving between rows.
Screw the boards in place using backerboard screws and an electric screwdriver. Space the screws according to the directions specific to the Durock board in use. Start securing the boards in the center and work toward the outside edges, stopping about 5/8 inch from the edges. Do not place screws into any joists as this can cause damage to the boards due to floor movement.
Cover all seams with the alkali-resistant tape. Trowel a thin layer of thinset over the length and edges of the tape overlapping the boards to complete the installation.